Started Vette Today w/open Headers
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Joined: Feb 2004
Posts: 87
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From: albrightsville pa
Started Vette Today w/open Headers
I'm in the middle of my EM header install project. I have to size and weld up the pipes to connect to my BB exhaust system, so I figured let's hear it with open headers. WOW! it sounds sweet but the longer it ran it got richer and ran worst. My question, is this normal due the o2 sensors being so close to open air. I also have a hot cam and pcm's for less tune. I'm hoping it will run better once I connect the bullet cats and the rest of the exhaust system.
Drifting
Joined: Jan 2003
Posts: 1,894
Likes: 3
From: Reading PA.
Did it run bad before it warmed up? Did it run bad with the stock exhaust system on it? One symptom of Injectors going bad is they start to run poorly after it warms up. Also I had a problem with my 90 Vette with it running Rich and it's cause was the coolant temp. sensor. Just a few thoughts. Let us know how ya make out and good luck with the fix. 
Pipe
Pipe
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
"is this normal due the o2 sensors being so close to open air"
Yes and you also have the possibilty of needing a heated O2 sensor like some of us with headers (depends on sensor position ) as the sensor cools off at idle and drops the ECM back to open loop.
Needs to be at correct temp to work.
Yes and you also have the possibilty of needing a heated O2 sensor like some of us with headers (depends on sensor position ) as the sensor cools off at idle and drops the ECM back to open loop.
Needs to be at correct temp to work.
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
LT4's had heated o2 sensors.
I ran my car with EM headers and Dynatech Powercats for several miles with the cat-back disconnected, and don't remember it smelling too rich.
With the open headers and cam, it sure did sound mean. Felt like someone was under the car beating on the floorboard.
I ran my car with EM headers and Dynatech Powercats for several miles with the cat-back disconnected, and don't remember it smelling too rich.
With the open headers and cam, it sure did sound mean. Felt like someone was under the car beating on the floorboard.
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Joined: Feb 2004
Posts: 87
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From: albrightsville pa
Did it run bad before it warmed up? Did it run bad with the stock exhaust system on it? One symptom of Injectors going bad is they start to run poorly after it warms up. Also I had a problem with my 90 Vette with it running Rich and it's cause was the coolant temp. sensor. Just a few thoughts. Let us know how ya make out and good luck with the fix. Pipe
Pipe
Thread Starter
Advanced
Joined: Feb 2004
Posts: 87
Likes: 0
From: albrightsville pa
I'm in the middle of my EM header install project. I have to size and weld up the pipes to connect to my BB exhaust system, so I figured let's hear it with open headers. WOW! it sounds sweet but the longer it ran it got richer and ran worst. My question, is this normal due the o2 sensors being so close to open air. I also have a hot cam and pcm's for less tune. I'm hoping it will run better once I connect the bullet cats and the rest of the exhaust system.
fires?
Race Director
Joined: Jan 2002
Posts: 12,263
Likes: 86
From: O'Fallon Missouri
I've been running EM headers and Dynatech Powercats in the same location for 4 years without a problem. My trans tunnel has always been hot, even with the stock exhaust.
I like your idea of the heat shield.
I like your idea of the heat shield.
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Thread Starter
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Joined: Feb 2004
Posts: 87
Likes: 0
From: albrightsville pa
I don't know about the shield being a good idea, which I have mounted to the floor, gets to hot to touch after a few minutes. I felt behind the carpet and touched one of the screws and it was real hot, How close is your cat to the floor.
